Books generally aren't written for players this strong, and I can tell you that there are no such books written recently on the Grunfeld, at least in English. If you somewhat like Dembo's book, why not just use Chessbase and update the lines yourself? If you are 2300, you're fully capable.

I have ELO>2300 and am a recently ardent Grünfeld player. I have Dembo's Play the Grünfeld, but that was published 2007 and has some lines I find slightly questionable, although most of the repertoire is fairly stable. I know Rowson's Understanding the Grünfeld is almost a Grünfeld aficionado's Bible, but that was published in 1999, and I don't know how useful it would be to me. I am not a club player; instead I am aiming to gain IM norms, so theoretical detail would be quite important.

I know Avrukh is writing GM Repertoire 8 on the Grünfeld, but I will tell anyone right now that this would probably not be out until summer 2011. The GM Rep books take an enormous amount of time to write and edit. 

However, I presently need a good Grünfeld book that is quite updated. I cannot seem to find any. Does anyone know of any other good Grünfeld books for competitive, highly rated readers (ELO>2300) that were published recently, other than Rowson's book or Dembo's book?

Thanks in advance